Add intersections function #41
Description
We have union, unions, and intersection, but no intersections.
I've been using this locally:
intersections :: forall f a. Foldable f => Ord a => f (Set a) -> Set a intersections sets = case List.fromFoldable sets of Nil -> Set.empty (x : xs) -> foldl intersection x xsPR with tests and docs on the todo list.